Some flash memory employs an oxide liner to achieve a square profile of its word-line spacer although a fence is formed as a consequence of this method. In order to sustain a higher word-line spacer (for better formation of LDD spacers) and a strong fence (to prevent collapse) it necessary to have less oxide break-through and poly over-etch time which then causes a serious word line bridge issue and particle issues.
In the prior art, the serious bridge issue of the word-line spacers occurs due to insufficient over-etching or producing a weak fence at the side wall of the poly spacer during the break-through etch step.
U.S. Pat. No. 6,599,797 B1 to Hofmann et al. discloses and SOI DRAM without a floating body effect.
U.S. Pat. No. 5,084,406 to Rhodes et al. discloses a method for forming low resistance DRAM digit-line.